The present invention relates to a jig for positioning and fixing a workpiece, and more particularly to a jig which can position a workpiece with respect to a workbench of a machine tool such as a pressing machine or a cutting machine and clamp the workpiece.
As a jig for positioning and fixing a workpiece, the applicant of this application proposes one disclosed in Japanese Laid-Open Patent Publication No. Hei 10-231091. As shown in FIG. 9, this jig includes a base member 32 mounted on the upper face of a table 31, and an adjustment member 33 screwed into a screw hole 32a of the base member 32. Further, this jig includes a bolt 34 and a first nut 35. The bolt 34 is inserted into the screw hole 32a of the base member 32 and a through hole 33b formed in the center of the adjustment member 33. The bolt 34 is engaged and fixed to the table 31. The first nut 35 fixes the base member 32 and the adjustment member 33 to the table 31 in cooperation with the bolt 34.
When fixing a workpiece W, a clamp fitting 36 is mounted on a flange portion 33c integrally formed at the upper end portion of the adjustment member 33 and the workpiece W mounted on the upper face of the table 31. Then, a second nut 37 screwed into the bolt 34 is fastened and the clamp fitting 36 is pressed downward, thereby fixing the workpiece W to the table 31.
In the conventional jig, however, a space formed between the upper end face 32b of the base member 32 and the lower end face 33e of the flange portion 33c is not effectively utilized. Therefore, the clamp fitting 36 must be arranged as a separate member on the upper face of the flange portion 33c of the adjustment member 33, and the number of components of the jig is thereby increased, which results in the problem that manufacturing and assembling cannot readily be performed.
It is an objective of the present invention to eliminate the problem existing in the prior art and to provide a jig for positioning and fixing a workpiece, which can facilitate manufacture with the reduced number of components and easily perform the clamping operation.
To solve the above-described problem, according to the present invention, there is provided a jig for positioning and fixing a workpiece on a workbench. The jig has a first clamping member having a screw hole extending in the vertical direction. A second clamping member has an insertion hole extending in the vertical direction, also has a male screw portion screwed into the screw hole of the first clamping member so as to be capable of adjusting a position thereof. The second clamping member also includes a flange portion at the upper outer periphery. A fixing member pierces the screw hole of the first clamping member and the insertion hole of the second clamping member, and fixes the first and second clamping members to the workbench. A fastening member determines the position of a workpiece with respect to the workbench by utilizing the first and second clamping members fixed to the workbench by the fixing member, and fixes the workpiece which has moved to a space between the clamping face of the first clamping member and the flange portion of the second clamping member.